The present invention relates to a method and apparatus for utilizing a memory in a printer connected to a host computer or the like.
A conventional printer is known which is connected to a host computer or the like to store output data from the host computer or the like in a memory and to perform printing on the basis of the storage data. A built-in memory of a conventional printer of this type typically has a memory structure (i.e., address mapping), as shown in FIG. 4. Referring to FIG. 4, reference symbol M denotes a memory, and its address space consists of address 0000 to address FFFF. The least significant address location is assigned to a control ROM 1 for storing a printer control program. The upper address locations are then sequentially assigned to a character generator ROM 2 for storing printing characters, a working RAM 3 used for data processing or the like, and a data reception buffer RAM 4 for receiving data from a host computer or the like. The most significant address location is defined as an empty space 5. With this memory allocation, even if the empty space 5 is used as an expansion memory area, either the buffer memory or the character generator memory is expanded. Therefore, it is very difficult to expand both the buffer RAM and the character generator ROM.